The present invention relates to a shoe sole composition, and more particularly to an improved shoe sole composition made from at least one thermoplastic base material and an additive component such as polyamide microfibers, polyamide powder, or polyamide fibers in a homogenous or partly homogenous blend as will permit the selection of desired physical properties; a method of producing such a shoe sole, and a shoe having such a sole.
In the footwear industry manufacturers have strived to make quality shoes for various activities including walking and athletics. Shoes are currently made using various compositions, constructions, and processing techniques. The type of materials used for each part of the shoe are important for creating a quality shoe. The materials used for the shoe sole are especially important. In fact, many attempts have been made and continue to be made in an effort to make an improved shoe sole.
Traditional shoe sole materials include ethylene vinyl acetate (EVA), polyurethane (PU), rubber, and leather. For example, shoe soles made from rubber compositions have included synthetic resins (U.S. Pat. No. 4,434,518) or finely divided inorganic material (U.S. Pat. No. 5,150,905). Other materials that have been used in shoe soles include synthetic and vulcanized elastomers joined with thermoplastics (U.S. Pat. No. 5,624,994); fiber reinforced elastic sheets using staples oriented in a particular direction (U.S. Pat. No. 5,281,380); and plasticizers incorporated into polyamide (U.S. Pat. No. 4,977,213). These shoe sole materials do not have the abrasion resistance, durability, and strength desired by consumers. While each particular shoe has certain advantages, consumers still desire a shoe with improved quality, and manufacturers desire a process for making such a shoe that is faster and less costly.
Accordingly, there is a need in the art for a shoe sole composition that has greater strength, durability, abrasion resistance, and other desirable properties such as skid resistance, flexibility, and comfort.
The present invention addresses this need by providing a shoe sole with improved properties such as strength, durability, abrasion resistance, etc. The shoe sole is comprised of a thermoplastic base material formed in the shape of the shoe sole and containing therein an additive component such as polyamide microfibers, polyamide powder, polyamide fibers or mixtures thereof.
The present invention further provides a process for manufacturing such a shoe sole which can be less expensive and time-consuming than previous methods.
The present invention further provides a shoe with improved strength, durability, and abrasion resistance, and a relatively long useful life. The shoe comprises an upper and a midsole or lower surface contacting sole made from the shoe sole described herein.
These and other features and advantages of the present invention will be readily apparent from the following detailed description of the invention, the scope of the invention being set out in the appended claims.